1. Field of the Invention
The present invention relates to a color image forming device, and more particularly to a color image forming device in which toner is supplied to a developing device from a toner container located apart from the developing device.
2. Background Information
A color image forming device includes a plurality of developing units corresponding to a plurality of color toners. The developing units are arranged in several ways, such as in a lateral direction, around the photosensitive drum in a circumferential direction, and within a rotary frame located adjacent to the photosensitive drum.
A rotary developing device having a plurality of the developing units within the rotary frame is shown in Japanese Unexamined Patent Publication No. 62-182768. In this device, the rotary frame is rotatably located adjacent to the photosensitive drum and supports four color developing units. When the rotary frame is rotated, each of the developing units is sequentially placed opposite the photosensitive drum so as to develop each color.
In addition, other types of rotary developing devices have been proposed, for example, in Japanese Unexamined Patent Publication No. 10-198149 and Japanese Unexamined Patent Publication No. 2001-134045. Here, the rotary developing device includes a toner container located apart from the developing units supported by the rotary frame. In this device, the toner is supplied from the toner container to the developing units though a toner supply device including toner supply pipes.
When the toner container is located separate and apart from the developing device as mentioned above, it is also necessary to have a toner supply device. The toner supply device includes toner supply pipes as shown in Japanese Unexamined Patent Publication No. 10-198149, which should be located adjacent to the rotary developing device.
However, the photosensitive drum is located adjacent to the rotary developing device, and the laser light path, through which the laser light from the laser unit passes so as to be applied to the photosensitive drum, exists adjacent to the photosensitive drum. Accordingly, the toner supply pipes have to be located so as not to interfere with the light path, which means less flexibility in design. If the toner supply pipes are located so as to avoid the laser light path, the toner supply pipes may require additional installation space, thereby making it difficult to reduce the overall size of the image forming device.
It is an object of the present invention to reduce the size of an image forming device which includes a toner container apart from the developing device, by making effective use of the space for the toner supply device.